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Fuel Pump Calculator

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The Fuel Pump Calculator is a handy tool designed to estimate the fuel pump flow rate required for an engine, ensuring it performs efficiently without running short on fuel. This calculation is crucial for automotive enthusiasts, mechanics, and anyone involved in engine tuning or modifications. The calculator simplifies complex calculations into an easily understandable format, allowing users to determine the optimal fuel pump size for their needs.

Purpose and Functionality

The primary purpose of the Fuel Pump Calculator is to calculate the fuel pump flow rate necessary for an engine based on its horsepower (HP), Brake-Specific Fuel Consumption (BSFC), and fuel system efficiency. These variables play a significant role in determining how much fuel an engine requires to operate optimally under various conditions.

  • Horsepower (HP): This is the maximum power output of the engine.
  • Brake-Specific Fuel Consumption (BSFC): This measures the amount of fuel consumed per horsepower per hour. It varies depending on the engine type and conditions but is crucial for calculating the necessary fuel flow.
  • Efficiency: Represents the fuel system’s effectiveness, accounting for any potential losses. It is expressed as a decimal less than 1, with a common conservative estimate being 0.85 or 85% efficiency.

The formula used by the calculator is:

Fuel Pump Flow Rate (LPH) = (HP * BSFC) / Efficiency

Step-by-Step Example

Let’s calculate the fuel pump flow rate for an engine with 300 HP, a BSFC of 0.45 lbs/(HP*hour), and an efficiency of 85%. The steps are as follows:

  1. Convert BSFC to kilograms per hour (if using metric units):scssCopy codeBSFC in kg/(HP*hour) = 0.45 lbs/(HP*hour) * 0.453592
  2. Calculate the fuel pump flow rate in liters per hour (LPH):scssCopy codeFuel Pump Flow Rate (LPH) = (300 HP * 0.45 * 0.453592) / 0.85

This yields a required fuel pump flow rate of approximately 72.04 LPH.

Relevant Information Table

VariableDescriptionTypical Value(s)
HPHorsepower of the engineVaries (e.g., 300 HP)
BSFC (lbs/HP*hour)Fuel consumed per horsepower per hour0.45 (for gasoline engines)
EfficiencyFuel system efficiency0.85 (85%)
LPHLiters per hour (output)Calculated based on formula


The Fuel Pump Calculator serves as a critical tool for determining the right fuel pump capacity, ensuring engines operate efficiently without fuel shortages. By inputting the engine’s horsepower, the fuel consumption rate (BSFC), and the system’s efficiency, users can quickly calculate the necessary fuel pump flow rate in liters per hour. This calculator not only simplifies the process of optimizing an engine’s fuel system but also helps in preventing issues related to fuel supply, thereby ensuring the engine’s longevity and performance. Whether for professional automotive engineers or enthusiasts, understanding and utilizing the Fuel Pump Calculator can significantly impact the success of engine projects.

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